Power socket wrench



Jan. 16, 1962 E. M. CALKINS 3,016,775

POWER SOCKET WRENCH Filed March 1, 1960 i :fizz'antar Eugene M (a/kins United States Patent 3,016,775 POWER SOCKET WRENCH Eugene Moses Calkins, 8119 Knowles Lane,

El Paso, Tex. Filed Mar. 1, 1960, Ser. No. 12,181 1 Claim. (CI. 81-57) The present invention relates to an improved power socket wrench and particularly to a motor driven wrench handle assembly for running threaded members rapidly to their tightening position or for removing them after they have become loosened.

In many assembly and disassembly jobs threaded members such as bolts and nuts can be started and must be turned through a substantial number of revolutions before they are in position to be tightened. Heretofore it has been necessary to run the threaded members through the relatively free tiuning phase by hand or by rotating a hand wrench or working a ratchet wrench back and forth until the free threads are taken up. At that point the wrench can be eifectively used to apply the torque to tighten the threaded member. Not only does the free turning operation constitute a waste of the operators energy but it takes up a considerable amount of time thereby slowing up rapid assembly or disassembly operation.

In a preferred form, the power wrench of the present invention contemplates use for manually applying a high torque to tighten threaded members or to loosen them and provides advantages in speeding up operations by rapidly turning threaded members through the rotations necessary to bring them to tightening position or to remove them. In addition to mechanically rapidly turning threaded members, a feature of the invention permits utilization of the same wrench handle for manually tightening or loosening the threaded members. However the features of the invention are also applicable for mechanically tightening or loosening threaded members through hard turning rotation.

An object of the present invention is to provide an improved wrench handle which is motor driven and is capable of rapidly turning a threaded member through the free threading or relatively easy turning phase at a relatively rapid speed and can be used to manually torque the threaded member through the tightening or hard turning phase.

Another object of the present invention is to provide an improved power driven wrench handle capable of use for either loosening or tightening a threaded member and which can be used for power operation or manual operation without adjustment or time consuming conversion.

Another object of the invention is to provide an improved power driven wrench handle wherein the speed ratio can be readily and quickly changed.

A still further object of the invention is'to provide a power driven wrench handle with an improved power transmission frame which permits transmission of rotation from the motor to the socket driven by the wrench but which will not permit the motor to be rotated when the wrench is manually operated and a torque is placed on the socket.

Other objects and advantages will become more apparent with the teaching of the principles of the invention in connection with the disclosure of the preferred embodiments thereof in the specification, claim and drawings, in which:

FIGURE 1 is a side elevational view of a power wrench handle constructed in accordance with the principles of the present invention and being in position for driving a socket;

FIGURE 2 is a view partially in horizontal section taken substantially along line 11-11 of FIGURE 1;

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FIGURE 3 is a view partially in vertical section taken substantially along line III-III of FIGURE 2; and

FIGURE 4 is a sectional view taken substantially along line IV--IV of FIGURE 2.

As shown on the drawings:

As illustrated in FIGURE 1 the power wrench handle assembly is illustrated as having an elongated body which may be referred to as a frame member 10 and which over all constitutes a handle. The handle is shown with a removable socket 11 attached thereto for driving a threaded member such as a nut or a bolt.

The frame member 10 has a handle or a gripping portion 12 at one end for gripping by the operator. The gripping portion is hollow and serves as a housing for an electrical motor therein supplied with electricity through a cord 14. The electric motor provides the driving power for the wrench and as will be appreciated by those skilled in the art an air motor or other suitable motive means may be employed. At the other end of the frame member 10 is a rotatable socket connector 13 in the form of a rectangular stud which interchangeably receives and supports sockets such as 11. A ball detent or similar means may be provided for holding the sockets on the connector 13. The connector is rotatably mounted on the frame member as will be described.

Connected to the handle portion 12 is a shank 16 in the form of a hollow tube with a flange 17 at the end for receiving screws 18 to attach to the hollow handle portion 12. As illustrated the handle portion 12 which serves as a motor housing is conveniently cylindricaliy shaped for gripping by the operator so as to fit the operators hand and may be knurled or otherwise surfaced for convenience. A control switch 15 is mounted at the front end of the housing for the operator and this will be wired to turn the motor off and on. The switch 15 also controls the direction of operation of the motor and for this purpose may be a multi-positi'on switch having a first off position, a second on-forward position and a third on-reverse position. As will be appreciated separate switches may be employed or reversing drive means such as a reversing gearing may be utilized to reverse the direction of a drive shaft 20 which extends through the hollow shank 16 and which is connected to the motor.

At the other end of the shank 16 the frame member is provided with a head 19 that defines a housing for gearing for driving the connector 13. I

The head 19 has a removable cap 21 for purposes of assembly and therefore interchanging the gearing to change the drive ratio between the drive shaft 20 and the connector 13, as will be described. The cap 21 is held in place by screws 22 which extend down through holes in the cap 21 and are threaded into the lower portion of the head. I

The connector 13 is rotatably mounted in the head 19 and is driven by a rotary driving gear 23. Extending laterally on each side of the driving gear 23 are side shafts 24 and 25 which are substantially parallel to the drive shaft 20. The side shafts carry worm gears 26 and 27 in driving mesh with the rotary connector gear 23. The side shafts are driven by a cross shaft 28 which extends transversely of the axis of the connector and transversely of the drive shaft 20. The cross shaft has worm gears 29 and 30 at its ends which are drivingly meshed with gears at the ends of the side shafts 24 and 25 as illustrated by the gears 24a and 25a for the side shafts 24 and 25.

The cross shaft is driven from the main shaft 20 and for this purpose carries a centrally located gear 31 which is driven by a worm 32 on the drive shaft.

The Worm gear arrangement illustrated offers sufiicient frictional resistance that when the motor is turned off the wrench can be manually pivoted or torqued without driving the motor in reverse. That is, the torque resistance of the threaded member will not rotate the worm gears, although the power loss from the motor to the wrench socket is not significant. The motor is a relatively high speed motor, preferably of the universal type and the gearing is chosen to reduce the speed of the socket to a relatively low speed.

Located in the drive shaft is a slip clutch 33. In the event the threaded member offers substantial resistance the slip clutch 33 will permit slippage with continued rotation of the motor. This permits the operator to turn on the motor for running the threaded member down to its tightened position Without closely watching when the threaded member reaches its tightened position. When the tightened position is reached the increased torque resistance will cause the clutch 33 to slip and the motor can be turned off at the switch 15. Thereafter the operator can manually turn the wrench to bring the threaded member to the proper tightness. However, because of the resistance of the worm gears the slip clutch 33 will not receive sufficient torque to slip when the wrench is being manually turned.

The cross shaft 28 and the side shafts 24 and 25 are supported by suitable bearing surfaces'within the head 19. These are shown as plain bearings although ball bearings may be employed. The wrench head also provides a suitable bearing for one end of the drive shaft 20 while the other end is rotatably supported by the handle portion 12.

For various purposes different speed ratios may be desired between the motor and the connector 13. To accomplish a change in speed ratios the cap 21 can be removed and the cross shaft 28 and side shafts 24 and 25 can be lifted out of their position. Replacement shafts may be then inserted utilizing gears 29 and 30 and gears on the shafts 24 and 25' that mesh therewith of different ratios. With the use of worm gears the ratio may be changed without changing the size of the gears. It will of course be recognized that although the preferred form is illustrated and described, other mechanical arrangements may be employed for changing the speed ratios. For example, the side gears 26 and 27 and the rotary gear 23 may be changed.

t will also be appreciated that while in the preferred form the worm gears offer a simple and automatic irreversible drive that permits manual torqueing of the wrench, in some environments other arrangements may be used to lock the drive when the wrench is to be manually operated.

In operation, the operator selects the socket 11 to fit the not or bolt to be threaded, and places the handle frame member in place. The motor is then turned on by the switch and the threaded member turned to tightening position. The motor is then turned off and the operator will then manually pull the wrench to bring the threaded member to the 'desired tightness. All this has been accomplished in a minimum time without reapplication of the wrench handle or changing or adjusting any of the parts.

The connector 13 is shown as provided with a rectangular socket 34 on the side opposite the stud for receiving and driving a member having a rectangular projection.

Thus it will be seen that I have provided an improved power Wrench handle which meets the objectives and advantages hereinbefore set forth. The mechanism is reliable in operation and inexpensive to manufacture and obtains a substantial saving in operational time and operator effort in both mass production assembly operations and intermittent uses.

The drawings and specification present a detailed disclosure of the preferred embodiments of the invention, and it is to be understood that the invention is not limited to the specific forms disclosed, but covers all modifications, changes and alternative constructions and methods falling within the scope of the principles taught by the invention.

I claim as my invention:

A power wrench handle comprising an elongated frame member having a handle portion and a rotatable socket connector mounted thereon with a stud projecting from one side of the connector and a socket on the other side of the connector, a driving motor connected to said frame member, a drive shaft supported on said frame member and connected to said motor, a head at one end of said frame member supporting said socket connector and defining a gear housing, a rotary gear connected to said connector and positioned in said housing, a pair of side shafts in said housing positioned on each side of said rotary gear in the plane of said gear and having worms drivingly meshing with said gear, a cross shaft in said housing extending across said side shafts transversely of the axis of said rotary gear and positioned laterally of the side shafts on the side of said socket in said connector,

first gear means connecting said cross shaft and said pair of shafts, a gear in the center of said cross shaft, and a meshing gear drivingly meshing with said center gear and connected to said drive shaft, said drive shaft being substantially in the plane of said pair of side shafts, said head and said housing projecting in the same general direction to enclose the socket side of the connector and said cross shaft.

References Cited in the file of this patent UNITED STATES PATENTS 

